     concepts))
 
 (defn- fetch-and-cache-metadata
-  "TODO
-   use this if we want to provide easy caching"
+  "Fetches metadata from Metadata DB for the given concept tuples and converts them into the format
+   requested. The original native format and the requested format are both stored in the cache."
   [context concept-tuples target-format]
   (let [mdb-context (context->metadata-db-context context)
 

   could make this a config (though need to make it a set)
   cached umm-json is the latest version"
  #{:echo10
    ;; TODO should we add other formats here?
    ;; Note that when upgrading umm version we should also cache the previous version of UMM.
    {:format :umm-json

    ;; Granule query. We don't cache those so just fetch from metadata db
    (fetch-metadata context concept-tuples target-format)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; Do the things below here make sense in this namespace?

;; TODO note that this isn't doing any caching and is really just a glorified faster search implementation.
;; It might make more sense for it to be implemented somewhere else. Or maybe the cache namespace here
